Field
An ejector and a refrigeration cycle apparatus including an ejector are disclosed herein.
Background
As is well known, a refrigeration cycle apparatus includes a compressor configured to compress a refrigerant, a high pressure side heat exchanger configured to cool the compressed refrigerant, an expansion device configured to depressurize and expand the refrigerant, and an evaporator configured to evaporate the refrigerant as the refrigerant absorbs latent heat. An ejector connected to each of a high pressure side heat exchanger and the evaporator is provided at a part of the refrigeration cycle apparatus.
The ejector used in the refrigeration cycle apparatus is configured to prevent loss occurring during an expansion process by expanding a high pressure refrigerant (main flow), and to reduce power consumption of the apparatus by increasing a pressure of a low pressure refrigerant (suction flow) discharged from an outlet of the evaporator. However, the conventional ejector and the refrigeration cycle apparatus having the same may have the following problems.
As a flow amount of a refrigerant passing through a nozzle is proportional to a sectional area (diameter, inner diameter) of a neck of the nozzle (a discharge side end), the sectional area (diameter, inner diameter) of the neck of the nozzle should be controlled in a sophisticated manner. More specifically, as the diameter of the neck of the nozzle requires precise dimension control so as to have a tolerance of several tens of microns (μm), it is not easy to process and fabricate the nozzle.
Second, even if a flow sectional area of the nozzle is formed through precise dimension control, if a pressure condition, such as a change in thermal load, is changed, an expansion deficiency or over-expansion of a refrigerant occurs. This may lower efficiency of the ejector.
In order to solve such problems, there has been proposed an ejector having a moveable needle capable of controlling a size of a diameter of a neck of a nozzle (a sectional area of a discharge side end of the nozzle), by relatively moving the needle with respect to the nozzle. However, the ejector having such a moveable needle, and a refrigeration cycle apparatus having the same may have the following problems. That is, as a nozzle is in a fixed state, only a diameter of a neck of the nozzle, a factor influencing efficiency of the ejector, may be controlled. In this case, a diameter of a low pressure refrigerant passage (flow path) formed outside of the nozzle, and a distance between the nozzle and a suction part or inlet are not controlled.